Plastic container and TDS

[moze229]

I regularly check the TDS reading from my RO/DI unit just to keep tabs on the DI resin. Today I checked it and it was 0. I checked my RO output and it was 2. Just for fun, I checked the reading in the container I store my DI water in and it was 42! What's up with that? I tested my tap water at 119. I then went back and tested the RO and DI outputs, with 2 and 0 as results, respectively. To my knowledge, there hasn't been anything to contaminate the container.

Should I continue to use this container? It's just a one gallon plastic container from the dollar store that I've been using for about three years. What's leaching from the container I wonder?

Matt

[lordofthereef]

What container are you using?

[moze229]

Originally Posted by lordofthereef

What container are you using?

It's just a one gallon plastic container from the dollar store that I've been using for about three years. There's nothing special, weird, or odd looking about it. I guess I should ask - is it common to see a TDS reading from water stored in plastic containers? The answer to that question will lead to my conclusion on whether or not to continue using it.

I've seen this once before in a Rubbermaid container I was using when I had a larger tank (25 gallon storage container) and I quit using it. Perhaps a TDS reading in DI water is normal in some containers?

Matt

[TeePee]

I think the water will tend to have an increased TDS reading as it sits around for an extended time period. So your zero TDS water will increase slightly as it sits in the container. Not sure if that comes from the container, the air, or what not. But your reading sure sounds very high though, so maybe your container is in fact leaching something into the water.

[Chiefsurfer]

how long does it sit when you get this reading? Also, is it covered and do you have forced hot air?

[JPags]

I have read that the TDS will increase to 1 or 2 when RO water is exposed to air but did not think it would go that high. The container may have been contaminated with something. I had a simular issue which phosphates leaching into my ro water from a rubbermade barrel I was using.

John

[moze229]

Originally Posted by TeePee

I think the water will tend to have an increased TDS reading as it sits around for an extended time period. So your zero TDS water will increase slightly as it sits in the container. Not sure if that comes from the container, the air, or what not. But your reading sure sounds very high though, so maybe your container is in fact leaching something into the water.

I would expect some dissolved solids after storage in almost ANY container, but not 42 As you state, I agree this is quite high.

Originally Posted by Chiefsurfer

how long does it sit when you get this reading? Also, is it covered and do you have forced hot air?

It is a gallon container, and it is used for top off water. I only go through a gallon or so every 3-4 days. It is a covered container - a 'Tupperware'-type container with a screw-on lid. Interesting question about the forced air - we do have forced heat via two heat pumps.

Originally Posted by JPags

I have read that the TDS will increase to 1 or 2 when RO water is exposed to air but did not think it would go that high. The container may have been contaminated with something. I had a simular issue which phosphates leaching into my ro water from a rubbermade barrel I was using.

To my knowledge, the container was not contaminated. It's always covered and has only been used for water. I've been using it for three years and never thought to check the TDS level - I only check what comes directly out of the RO/DI unit. The Rubbermaid container that I was using in the past that I had a TDS level with was at like 25 or something. You say that in your experience it was leaching phosphates - did you detect it with a test kit? I'm not detecting anything in the water with any of my test kits. Of course, 42 TDS is likely too low to read with any hobby test kit.

I'd like to know what the heck it is.

Matt

[Chiefsurfer]

my only thining about the forced hot air is that forced air throws around a LOT of stuff. Maybe if you are using a 1-gallon size, get a gallon of steam-distilled water(completely pure, AND filled so it would not have any "dust" or other particulate) and see if you get the same result. Don't necessarily throw the water out. Also try to take that "42" tds water, and throw it in glass. I doubt that will change anything, but it's worth a shot. May also pay to test multiple stages after making the pure water. Check time of 1 hr, 2 hr, 4 hr, 12hr, 1 day, 2 days, 3 days, etc. See if you get a natural progression, that would say more about the container than the water creating it's own tds.

[xgames]

Get a wine storage container.

[lordofthereef]

Originally Posted by moze229

It's just a one gallon plastic container from the dollar store that I've been using for about three years. There's nothing special, weird, or odd looking about it.

I would use something food grade. It is common to see the plastic degrade with water sitting in it (although not sure about numbers quite THAT high). Really anything you use for water storage, sump, etc. truly should either be made for salt/aquarium use or be food grade. I have even red about brute trashcans (whsich people on here seem to love) effecting water quality. No adverse effects were documented outside of coral spawning anomalies (lack of spawning actually), but there was a clear difference from water stored in a Brute versus other food grade containers.

[JPags]

Originally Posted by moze229

You say that in your experience it was leaching phosphates - did you detect it with a test kit? I'm not detecting anything in the water with any of my test kits. Of course, 42 TDS is likely too low to read with any hobby test kit.

I'd like to know what the heck it is.

Matt

I used a low range photo phosphate meter to check the water when I made it (Which was 0.0) and then several days later (which was .18). My other phosphate test kits never detected anything

John

[moze229]

Originally Posted by Chiefsurfer

my only thining about the forced hot air is that forced air throws around a LOT of stuff. Maybe if you are using a 1-gallon size, get a gallon of steam-distilled water(completely pure, AND filled so it would not have any "dust" or other particulate) and see if you get the same result. Don't necessarily throw the water out. Also try to take that "42" tds water, and throw it in glass. I doubt that will change anything, but it's worth a shot. May also pay to test multiple stages after making the pure water. Check time of 1 hr, 2 hr, 4 hr, 12hr, 1 day, 2 days, 3 days, etc. See if you get a natural progression, that would say more about the container than the water creating it's own tds.

Yeah, I just need to spend some more time with it. I figured that someone might come on and say, "Don't worry about it - they all do that" but I guess not I look into it a little more.

Matt

[moze229]

Originally Posted by lordofthereef

I would use something food grade. It is common to see the plastic degrade with water sitting in it (although not sure about numbers quite THAT high). Really anything you use for water storage, sump, etc. truly should either be made for salt/aquarium use or be food grade. I have even red about brute trashcans (whsich people on here seem to love) effecting water quality. No adverse effects were documented outside of coral spawning anomalies (lack of spawning actually), but there was a clear difference from water stored in a Brute versus other food grade containers.

Yeah. I suppose I might spend a little more on a food grade container. This one is just labeled '4-quart Screw Top Container' - doesn't say anything about food grade. I would imagine people use them to store food in though. I use the same containers to store Randy's two-part too. Now I'm rethinking the whole thing

Matt

[moze229]

Originally Posted by JPags

I used a low range photo phosphate meter to check the water when I made it (Which was 0.0) and then several days later (which was .18). My other phosphate test kits never detected anything

John

"I see" said the blind man. I wish I had such a device to check mine. I'm just curious what I might find the TDS to be.

Matt

[lordofthereef]

Originally Posted by moze229

Yeah. I suppose I might spend a little more on a food grade container. This one is just labeled '4-quart Screw Top Container' - doesn't say anything about food grade. I would imagine people use them to store food in though. I use the same containers to store Randy's two-part too. Now I'm rethinking the whole thing

Matt

It is not that it is necessarily unsafe to store food in, but something rated for food grade will not degrade. Rubbermaid makes some food storage containers that are actually considered food grade. Generally speaking this isn't the "totes" and similar Rubbermaid products found in walmart though.

Also, are you just storing the DRY two part in this? I wouldn't worry much over that. It is when you get liquids that you have more of the problems.

[moze229]

Originally Posted by lordofthereef

Also, are you just storing the DRY two part in this? I wouldn't worry much over that. It is when you get liquids that you have more of the problems.

No - it's the mixed buffer itself. That was my concern.

Matt

[luther1200]

Just go get a gallon of distilled water and use the gallon jug after you use it.

[FranktheTankTx]

I can help! I had an acrylic storage container for RO/DI water which would be used for ATO. One day I tested the water contained in the acrylic container & it tested off the charts TDS. I totally freaked out & emptied the container, washed it out, & put fresh RO/DI water in the container. The next day, the TDS readings were present!! I freaked out again!!

So what did I find?

I find that RO/DI water gets TDS from air easily. It doesn't take long before 0 TDS water becomes 5-10 or 20 TDS water. Also, since I had an ATO installed to this acrylic container, I noticed that there was some possibility for slight back siphoning of saltwater from the sump - probable only mml but enough to effect TDS readings furthermore.

Have you ever tested saltwater? It's full of TDS. TDS isn't all bad. It's just somethings that we don't want which are detected with a TDS meter.

The fact is, once you start with 0 TDS, you aren't going to finish with 0 TDS. You'll get TDS in a matter of short time unless it's contained in an air tight container. The good news is, you know that your RO/DI unit stripped the water of all contaminents prior to use. The TDS you are reading is not the TDS your tap water contains.

Conclusion: Nothing to worry about.

[EdSnyder]

Originally Posted by FranktheTankTx

I can help! I had an acrylic storage container for RO/DI water which would be used for ATO. One day I tested the water contained in the acrylic container & it tested off the charts TDS. I totally freaked out & emptied the container, washed it out, & put fresh RO/DI water in the container. The next day, the TDS readings were present!! I freaked out again.

What exactly is, "off the charts"?

[moze229]

Originally Posted by FranktheTankTx

I can help! I had an acrylic storage container for RO/DI water which would be used for ATO. One day I tested the water contained in the acrylic container & it tested off the charts TDS. I totally freaked out & emptied the container, washed it out, & put fresh RO/DI water in the container. The next day, the TDS readings were present!! I freaked out again!!

So what did I find?

I find that RO/DI water gets TDS from air easily. It doesn't take long before 0 TDS water becomes 5-10 or 20 TDS water. Also, since I had an ATO installed to this acrylic container, I noticed that there was some possibility for slight back siphoning of saltwater from the sump - probable only mml but enough to effect TDS readings furthermore.

Before an earlier post, I had never considered air contamination. But 42 sounds a little high for water that's been sitting in a covered container for 3-4 days to me.

Originally Posted by FranktheTankTx

Have you ever tested saltwater? It's full of TDS. TDS isn't all bad. It's just somethings that we don't want which are detected with a TDS meter.

I never tested saltwater with my TDS meter - I already know that it has dissolved solids. I measure those with a refractometer

Originally Posted by FranktheTankTx

The fact is, once you start with 0 TDS, you aren't going to finish with 0 TDS. You'll get TDS in a matter of short time unless it's contained in an air tight container. The good news is, you know that your RO/DI unit stripped the water of all contaminents prior to use. The TDS you are reading is not the TDS your tap water contains.

Conclusion: Nothing to worry about.

Likely so. As stated, I've been using these containers for over three years now with no problems that I know of. I was just wondering what others would say about the reading from the container. I just found it peculiar.

Matt

[FranktheTankTx]

Originally Posted by EdSnyder

What exactly is, "off the charts"?

I honestly don't know/remember. This has been several months ago when I ran into this scenario. But like the OP, I freaked out when I read TDS in my RO/DI container. Then I realized there is really nothing I can do about it once I add it to my ATO container.

I'd be interested in everyone else's TDS readings in their containers of RO/DI water waiting to be used or actively being used as your ATO.

[stubby 58]

Have a 36gal rubber maid tote with lid water has been in it for a week , just checked it TDS .03 . I have not made it a habit to check water in tote . I always run water into a plastic baggie when I make water it is normally 0 . Never tough to check the tote . Gary

[lordofthereef]

Originally Posted by FranktheTankTx

Have you ever tested saltwater? It's full of TDS. TDS isn't all bad. It's just somethings that we don't want which are detected with a TDS meter.

Unless you have a totally freaking sweet meter, you are going to get an error testing saltwater.

I would also say that if you are getting 0TDS water to read over 20 just by leaving it in the air, you need to check the air filters in your house, or just accept that your air is really polluted. I just did a test for good measure. We drink RO water (bipass the DI) which tests 2-5 generally. I had a glass of water sitting on my nightstand that I just tested (prompted by your post). It tested at 6-7. Air itself, unless it is really polluted and filled with particles, shouldn't really raise your TDS, especially not from 0 to 40+

[lordofthereef]

Originally Posted by FranktheTankTx

I honestly don't know/remember. This has been several months ago when I ran into this scenario. But like the OP, I freaked out when I read TDS in my RO/DI container. Then I realized there is really nothing I can do about it once I add it to my ATO container.

I'd be interested in everyone else's TDS readings in their containers of RO/DI water waiting to be used or actively being used as your ATO.

To be fair my system utilized a 5g pressurized jug, meaning the water goes in and there is really no chance of contamination. It has always (and currently) read under 1. Right now I am getting .02 and it has been in there (at least a portion of it) I would say for about 2 weeks. I do remove it into another container so that it can be properly aerated when added to my system.

[FranktheTankTx]

Originally Posted by lordofthereef

Unless you have a totally freaking sweet meter, you are going to get an error testing saltwater.

I would also say that if you are getting 0TDS water to read over 20 just by leaving it in the air, you need to check the air filters in your house, or just accept that your air is really polluted. I just did a test for good measure. We drink RO water (bipass the DI) which tests 2-5 generally. I had a glass of water sitting on my nightstand that I just tested (prompted by your post). It tested at 6-7. Air itself, unless it is really polluted and filled with particles, shouldn't really raise your TDS, especially not from 0 to 40+

I thought I stated that my ATO would back siphon when the pump shut off so I constantly pulled some saltwater back into the container. While it was very little - over time it would produce a TDS reading.

I doubt the air was causing the high TDS reading, but more so the saltwater. Though, I know air will cause some TDS reading over time.

And yes, I had a really nice TDS mete - I could get a reading from saltwater.